Diatoms also incorporate various hexoses and pentoses directly into their cell walls [51]. While we did not separate storage vs. structural carbohydrates using our methodology, we hypothesize that the ratio of storage:structural carbohydrates increased from dawn to dusk to store photosynthate for metabolism at night [49] and [50]. Our observations of carbohydrate are lower than previously observed for this species [23], [34] and [52]. This may be due to our utilization of an improved MBTH-based vs. phenol-sulfuric acid or anthrone based assays which can overestimate carbohydrate content [3